1. Field of the Invention
This invention relates to a closure system to seal the joints between the abutting side edges of insulating foam panels used in wall and roof construction, especially in metal buildings.
2. Description of the Prior Art
Prefabricated foam panels are widely used to form an insulating envelope for insulating building walls and roofs. The overall insulating efficiency of the array of foam panels of the wall or roof system is influenced by the nature of the closure and seal arrangement used at the junction of the panels.
Currently, there are a variety of joint closures, including tapes, PVC strips, caulks and other sealants. These closures are installed at the job site, where care must be taken to ensure proper performance. The PVC strips are recommended, but they are relatively expensive and accordingly are replaced frequently by the less expensive tapes or sealants. Unfortunately, application of the latter closures is time consuming and difficult.
Furthermore, besides their expensiveness, the PVC strips usually recommended have other serious shortcomings. Their dimensional stability is relatively poor. In service in metal buildings, the PVC strips tend to twist and deform due to roof top temperatures, creating uninsulated areas where condensation can form and drop from the ceiling. It is also necessary to have a separate PVC profile for each insulation board thickness. Additionally, the PVC profiles are only 10' long, requiring cutting the length to fit the span between wall girts and ceiling purlins, resulting in inefficient, expensive use. More often than not, the PVC profiles do not adequately match-up to the board thickness, resulting in either a very tight, stressed fit or a very loose fit. Also, a sealant that must be field applied is also required to permanently attach the PVC strip and prevent air infiltration through the strip and insulation board interface.